"We don't want to be thinking too much about this game," he told MUTV. "We have lost two points, but the season is long and we have our next game on Wednesday. We need to think about our mistakes and, next time, score.
"It is a difficult game away, but we go there to win like always. Three points is three points, home or away, we don't need to think. If we worry about this game, it is not good for us because we always need to look forward."
Vidic is disappointed to have lost Rooney to injury so early in the season, but he is hopeful that United's enlarged squad can help compensate for his absence.
"I think Wayne was a big loss," said the Serbian. "He showed in pre-season that he's been working hard and playing very well. I think he's an important player for us.
"But we also have new players and players who have the ability to play well and score goals. We have a big squad, and what is good this season is that we have big competition."